Neutrophils in innate and adaptive immunity

The prognostic value of the systemic immune inflammation index in patients with IgA nephropathy

BACKGROUND

Immune and inflammatory factors are considered the basic underlying mechanisms of IgA nephropathy (IgAN). The systemic immune inflammation index (SII) is a new inflammatory biomarker and has been identified as a prognostic indicator for various diseases. However, limited studies have been conducted on the prognostic value of the SII in patients with IgAN, and we aimed to address this gap.

METHODS

A total of 374 patients with IgAN confirmed by renal biopsy performed from 1 January 2015 to 1 April 2019, were retrospectively included. The follow-up period of all patients was at least 12 months after diagnosis, and the endpoint was defined as end-stage kidney disease (ESKD). Patients were further divided into a high-risk group (SII ≥ 456.21) and a low-risk group (SII < 456.21) based on the optimal cutoff value of the SII determined by receiver operating characteristic (ROC) curve analysis. Baseline clinicopathological parameters were compared between the groups, and Cox proportional hazards analyses and Kaplan-Meier analysis were performed to assess renal survival in IgAN patients.

RESULTS

After a median follow-up period of 32.5 months, a total of 53 patients eventually reached ESKD. Patients in the high-SII group tended to have a lower hemoglobin level (p = 0.032) and eGFR (p < 0.001), a higher serum creatinine level (p = 0.023) and 24-hour total protein level (p = 0.004), more severe tubular atrophy and interstitial fibrosis (p = 0.002) and more crescents (p = 0.030) than did those in the low-SII group. Univariate and multivariate Cox regression analyses demonstrated that an SII ≥456.21 was an independent risk factor for poor renal survival in IgAN patients (HR 3.028; 95% CI 1.486-6.170; p = 0.002). Kaplan-Meier analysis revealed that a high SII was significantly associated with poor renal prognosis (p < 0.001) and consistently exhibited remarkable discriminatory ability across different subgroups in terms of renal survival.

CONCLUSION

A high SII was associated with more severe baseline clinical and pathological features, and an SII ≥456.21 was an independent risk factor for progression to ESKD in IgAN patients.

Dysregulation of neutrophil extracellular traps (NETs)-related genes in the pathogenesis of diabetic kidney disease - Results from bioinformatics analysis and translational studies

The role of Neutrophil extracellular traps (NETs) in the immunopathogenesis of Diabetic Kidney Disease (DKD) remains elusive. We used a machine learning approach to identify differentially expressed genes (DEGs) associated with NETs in human DKD kidney biopsy datasets and validated the results using single-nucleus RNA sequencing datasets. The expressions of these candidate genes and related cytokines were verified in blood obtained from DKD patients. Three NETs-associated genes (ITGAM, ITGB2 and TLR7) were identified, which all showed significant upregulation in both glomerular and tubulointerstitial compartments in human DKD kidneys. DKD patients showed significantly higher number of activated neutrophils with increased ITGAM and ITGB2 expression, higher serum IL-6 but lower IL-10, compared to healthy controls (p all <0.01). This study suggests that dysregulation of NETs-associated genes ITGAM and ITGB2 are related to the pathogenesis of DKD, and may serve as novel diagnostic markers and therapeutic targets in DKD.

Hydroalcoholic extract of Araucaria sp. brown propolis alleviates ulcerative colitis induced by TNBS in rats by reducing inflammatory cell infiltration and oxidative damage

OBJECTIVE

To investigate the effects of Araucaria sp. brown propolis (ABP) against trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats.

METHODS

Animals received vehicle (1% DMSO, 1 ml/kg) or hydroalcoholic extract of ABP (hydroalcoholic extract of Araucaria sp. brown propolis (HEABP), 30, 100, and 300 mg/kg) orally, or dexamethasone (25 mg/kg, s.c.) for 5 days. On day 4, the animals received intracolonic TNBS (150 mg/kg), on day 6 they were euthanized. The weight of the animals, the macroscopic and microscopic colonic damage, reduced glutathione (GSH) and malondialdehyde (MDA) levels, and the activity of glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), and myeloperoxidase (MPO) were measured in colon homogenate. The action of HEABP and two isolated compounds in neutrophil migration was recorded.

KEY FINDINGS

HEABP (100 and 300 mg/kg), but not dexamethasone, decreased colonic lesion, and increased colonic mucin staining. In parallel, HEABP decreased MDA and restored GSH levels and the activity of SOD, CAT, and GST in the colon. A dose-dependent inhibition of MPO activity was observed (LogIC50 = 1.9). Moreover, HEBPA and the junicedric and abietic acids inhibited the neutrophil chemotaxis in vitro and HEBPA reduced neutrophil migration in vivo.

CONCLUSION

HEABP may be promising in the therapies for inflammatory bowel diseases, reducing oxidative and inflammatory damage, especially mediated by neutrophils.

Protective immune response against Rhodococcus equi: An innate immunity-focused review

Rhodococcus equi causes pyogranulomatous pneumonia in foals and immunocompromised people. Despite decades of research efforts, no vaccine is available against this common cause of disease and death in foals. The purpose of this narrative review is to summarise the current understanding of interactions between R. equi and the host innate immune system, to describe features of the immune response that are associated with resistance or susceptibility to R. equi infection, and help guide strategies for developing novel approaches for preventing R. equi infections. Virulence of R. equi in foals has been attributed to the virulence associated protein A which allows intracellular survival in macrophages by preventing acidification of R. equi-containing vacuole. Additionally, foal susceptibility to R. equi infection is associated with immaturity and naivety of innate and adaptive immune systems, while adult horses with fully functional immune system are resistant to pneumonia. Specific interaction between R. equi and innate immune cells can result in bacterial survival or death; learning how to manipulate these responses to control infection is critical to prevent pneumonia in foals. Administration of live vaccines and stimulation of innate immune responses appears to improve foals' immune response and has the potential to overcome the challenges of foal active vaccination and elicit protection against pneumonia.

Role of Hyaluronic acid and its chemical derivatives in immunity during homeostasis, cancer and tissue regeneration

Over the last few decades, scientists have recognized the critical role that various components of the extracellular matrix (ECM) play in maintaining homeostatic immunity. Besides, dysregulation in the synthesis or degradation levels of these components directly impacts the mechanisms of immune response during tissue injury caused by tumor processes or the regeneration of the tissue itself in the event of damage. ECM is a complex network of protein compounds, proteoglycans and glycosaminoglycans (GAGs). Hyaluronic acid (HA) is one of the major GAGs of this network, whose metabolism is strictly physiologically regulated and quickly altered in injury processes, affecting the behavior of different cells, from stem cells to differentiated immune cells. In this revision we discuss how the native or chemically modified HA interacts with its specific receptors and modulates intra and intercellular communication of immune cells, focusing on cancer and tissue regeneration conditions.

Nanoparticle-neutrophils interactions for autoimmune regulation

Neutrophils play an essential role as 'first responders' in the immune response, necessitating many immune-modulating capabilities. Chronic, unresolved inflammation is heavily implicated in the progression and tissue-degrading effects of autoimmune disease. Neutrophils modulate disease pathogenesis by interacting with the inflammatory and autoreactive cells through effector functions, including signaling, degranulation, and neutrophil extracellular traps (NETs) release. Since the current gold standard systemic glucocorticoid administration has many drawbacks and side effects, targeting neutrophils in autoimmunity provides a new approach to developing therapeutics. Nanoparticles enable targeting of specific cell types and controlled release of a loaded drug cargo. Thus, leveraging nanoparticle properties and interactions with neutrophils provides an exciting new direction toward novel therapies for autoimmune diseases. Additionally, recent work has utilized neutrophil properties to design novel targeted particles for delivery into previously inaccessible areas. Here, we outline nanoparticle-based strategies to modulate neutrophil activity in autoimmunity, including various nanoparticle formulations and neutrophil-derived targeting.

The Role of Neutrophils in Multiple Sclerosis and Ischemic Stroke

Inflammation plays an important role in numerous central nervous system (CNS) disorders. Its role is ambiguous-it can induce detrimental effects, as well as repair and recovery. In response to injury or infection, resident CNS cells secrete numerous factors that alter blood-brain barrier (BBB) function and recruit immune cells into the brain, like neutrophils. Their role in the pathophysiology of CNS diseases, like multiple sclerosis (MS) and stroke, is highly recognized. Neutrophils alter BBB permeability and attract other immune cells into the CNS. Previously, neutrophils were considered a homogenous population. Nowadays, it is known that various subtypes of these cells exist, which reveal proinflammatory or immunosuppressive functions. The primary goal of this review was to discuss the current knowledge regarding the important role of neutrophils in MS and stroke development and progression. As the pathogenesis of these two disorders is completely different, it gives the opportunity to get insight into diverse mechanisms of neutrophil involvement in brain pathology. Our understanding of the role of neutrophils in CNS diseases is still evolving as new aspects of their activity are being unraveled. Neutrophil plasticity adds another level to their functional complexity and their importance for CNS pathophysiology.

Circadian disturbances by altering the light-dark cycle negatively affects hematopoietic function of bone marrow in mice

Circadian rhythms in metabolically active tissues are crucial for maintaining physical health. Circadian disturbance (CD) can cause various health issues, such as metabolic abnormalities and immune and cognitive dysfunctions. However, studies on the role of CD in immune cell development and differentiation, as well as the rhythmic expression of the core clock genes and their altered expression under CD, remain unclear. Therefore, we exposed C57bl/6j mice to repeated reversed light-dark cycles for 90 days to research the effects of CD on bone marrow (BM) hematopoietic function. We also researched the effects of CD on endogenous circadian rhythms, temporally dependent expression in peripheral blood and myeloid leukocytes, environmental homeostasis within BM, and circadian oscillations of hematopoietic-extrinsic cues. Our results confirmed that when the light and dark cycles around mice were frequently reversed, the circadian rhythmic expression of the two main circadian rhythm markers, the hypothalamic clock gene, and serum melatonin, was disturbed, indicating that the body was in a state of endogenous CD. Furthermore, CD altered the temporally dependent expression of peripheral blood and BM leukocytes and destroyed environmental homeostasis within the BM as well as circadian oscillations of hematopoietic-extrinsic cues, which may negatively affect BM hematopoiesis in mice. Collectively, these results demonstrate that circadian rhythms are vital for maintaining health and suggest that the association between CD and hematopoietic dysfunction warrants further investigation.

Surgical stress induced tumor immune suppressive environment

Despite significant advances in cancer treatment over the decades, surgical resection remains a prominent management approach for solid neoplasms. Unfortunately, accumulating evidence suggests that surgical stress caused by tumor resection may potentially trigger postoperative metastatic niche formation. Surgical stress not only activates the sympathetic-adrenomedullary axis and hypothalamic-pituitary-adrenocortical axis but also induces hypoxia and hypercoagulable state. These adverse factors can negatively impact the immune system by downregulating immune effector cells and upregulating immune suppressor cells, which contribute to the colonization and progression of postoperative tumor metastatic niche. This review summarizes the effects of surgical stress on four types of immune effector cells (neutrophils, macrophages, natural killer cells and cytotoxic T lymphocytes) and two types of immunosuppressive cells (regulatory T cells and myeloid-derived suppressor cells), and discusses the immune mechanisms of postoperative tumor relapse and progression. Additionally, relevant therapeutic strategies to minimize the pro-tumorigenic effects of surgical stress are elucidated.

MARCKS Inhibition Alters Bovine Neutrophil Responses to Salmonella Typhimurium

Neutrophils are innate immune cells that respond quickly to sites of bacterial infection and play an essential role in host defense. Interestingly, some bacterial pathogens benefit from exuberant neutrophil inflammation. Salmonella is one such pathogen that can utilize the toxic mediators released by neutrophils to colonize the intestine and cause enterocolitis. Because neutrophils can aid gut colonization during Salmonella infection, neutrophils represent a potential host-directed therapeutic target. Myristoylated alanine-rich C-kinase substrate (MARCKS) is an actin-binding protein that plays an essential role in many neutrophil effector responses. We hypothesized that inhibition of MARCKS protein would alter bovine neutrophil responses to Salmonella Typhimurium (STm) ex vivo. We used a MARCKS inhibitor peptide to investigate the role of MARCKS in neutrophil responses to STm. This study demonstrates that MARCKS inhibition attenuated STm-induced neutrophil adhesion and chemotaxis. Interestingly, MARCKS inhibition also enhanced neutrophil phagocytosis and respiratory burst in response to STm. This is the first report describing the role of MARCKS protein in neutrophil antibacterial responses.

Type 1 diabetes mellitus: Roles of neutrophils in the pathogenesis

Circulating neutrophil counts are reduced both in healthy autoantibody-positive individuals and in patients with type 1 diabetes, which may be related on cell-specific autoimmunity. This paper was written to give an update on roles of neutrophils in the pathogenesis of type 1 diabetes mellitus. Different research search engines like PubMed Central, Scopus, Web of Science, Researchgate, Google Scholar etc were utilised for writing this paper. A drop in blood neutrophil counts in type 1 diabetes may be caused by decreased neutrophil generation and maturation, tissue maintenance, consumption, or peripheral damage. Neutrophil count variations between studies may be explained by results from various stages of diabetes or by ethnic groups. Neutrophils can induce type 1 diabetes by colonizing pancreatic islets and interacting with other immune cells, according to exciting findings that shed new light on their role in the pathogenesis of the disease. Knowing more about the function of neutrophils in the pathogenesis of type 1 diabetes will help in early diagnosis, treatment, and even prevention of the disease.

Keratinocyte FABP5-VCP complex mediates recruitment of neutrophils in psoriasis

One of the hallmarks of intractable psoriasis is neutrophil infiltration in skin lesions. However, detailed molecular mechanisms of neutrophil chemotaxis and activation remain unclear. Here, we demonstrate a significant upregulation of epidermal fatty acid binding protein (E-FABP, FABP5) in the skin of human psoriasis and psoriatic mouse models. Genetic deletion of FABP5 in mice by global knockout and keratinocyte conditional (Krt6a-Cre) knockout, but not myeloid cell conditional (LysM-Cre) knockout, attenuates psoriatic symptoms. Immunophenotypic analysis shows that FABP5 deficiency specifically reduces skin recruitment of Ly6G+ neutrophils. Mechanistically, activated keratinocytes produce chemokines and cytokines that trigger neutrophil chemotaxis and activation in an FABP5-dependent manner. Proteomic analysis further identifies that FABP5 interacts with valosin-containing protein (VCP), a key player in NF-κB signaling activation. Silencing of FABP5, VCP, or both inhibits NF-κB/neutrophil chemotaxis signaling. Collectively, these data demonstrate dysregulated FABP5 as a molecular mechanism promoting NF-κB signaling and neutrophil infiltration in psoriasis pathogenesis.

A novel neutrophil extracellular traps-related lncRNA signature predicts prognosis in patients with early-stage lung adenocarcinoma

BACKGROUND

Neutrophil extracellular traps (NETs) could entrap tumour cells and promote their dissemination and metastasis. Further analysis of NETs-related molecules is expected to provide a new strategy for prognosis prediction and treatment of lung adenocarcinoma (LUAD) patients.

METHODS

The model construction was established through co-expression analysis, Lasso Cox regression, univariate and multivariate COX regression, Gene ontology and Kyoto Encyclopedia of Genes and Genomes pathway. The potential drugs and analysed drug sensitivity were screened by pRRophetic packages.

RESULTS

In this study, we constructed a 15 NETs-related long non-coding RNAs (lncRNAs) prognostic prediction model (AC091057.1, SPART-AS1, AC023796.2, AL031600.2, AC084781.1, AC032011.1, FAM66C, C026355.2, AL096870.2, AC092718.5, PELATON, AC008635.1, AL162632.3, AC087501.4 and AC123768.3) for patients with early-stage LUAD based on public databases and datasets. The signature is associated with immune cell functions, tumour mutation burden and treatment sensitivity in LUAD patients. Additionally, we found that FAM66C is highly expressed in lung cancer patients for the first time, which is associated with poor prognosis. FAM66C knockdown significantly inhibited the proliferation and migration ability of the tumour cells.

CONCLUSIONS

In conclusion, this model is a new and effective prognostic and efficacy predictive biomarker, FAM66C plays an oncogene role in the process of LUAD development. It may provide a new theoretical basis for the clinical diagnosis and treatment in LUAD patients in early stage.

BALB/c and C57BL/6 mice differ in oxidant and antioxidant responses in innate and adaptive immune cells in an asthma model induced by cockroach allergens

Asthma is a complex and heterogenous disease affected by a multitude of factors. Several phenotypes of asthma exist which are influenced by various molecular mechanisms that include presence of antioxidant and oxidant enzymes in different immune cells such as dendritic cells (DCs), alveolar macrophages (AMs), neutrophils, and T cells. Close interaction between epithelial cells and dendritic cells initiates complex pathogenesis of asthma followed by involvement of other innate and adaptive immune cells. In chronic phase of the disease, these immune cells support each other in amplification of airway inflammation where oxidant-antioxidant balance is known to be an important contributing factor. Genetic variability in antioxidant response may influence the development of airway inflammation, however it has not been studied in mice yet. The two most studied mice strains, i.e. BALB/c and C57BL/6 are reported to have dissimilar airway responses to the same allergens due to their genetic makeup. In this investigation, we explored whether these strains had any differences in pulmonary oxidant-antioxidant system (Nrf2, SOD2, iNOS, HO-1, nitrotyrosine) in different immune cells (DCs, AMs, neutrophils, T cells), airway inflammation (presence of eosinophils and/or neutrophils) and mucus production in response to repeated cockroach allergen extract (CE) mouse model of asthma. Our data show that C57BL/6 mice had better induction of antioxidant system than BALB/c mice. Consequently, iNOS/nitrotyrosine levels were much exaggerated in BALB/c than C57BL/6 mice. As a result, BALB/c mice developed mixed granulocytic airway inflammation, whereas C57BL/6 developed mostly eosinophilic airway inflammation. Our data suggest that an exaggerated oxidant generation along with a weak antioxidant induction in response to a natural allergen on a susceptible genetic background may determine development of severe asthma phenotype such as mixed granulocyte inflammation.

Interactions between neutrophils and T-helper 17 cells

Neutrophils comprise the majority of immune cells in human peripheral circulation, have potent antimicrobial activities, and are clinically significant in their abundance, heterogeneity, and subcellular localization. In the past few years, the role of neutrophils as components of the innate immune response has been studied in numerous ways, and these cells are crucial in fighting infections, autoimmune diseases, and cancer. T-helper 17 (Th17) cells that produce interleukin 17 (IL-17) are critical in fighting infections and maintaining mucosal immune homeostasis, whereas they mediate several autoimmune diseases. Neutrophils affect adaptive immune responses by interacting with adaptive immune cells. In this review, we describe the physiological roles of both Th17 cells and neutrophils and their interactions and briefly describe the pathological processes in which these two cell types participate. We provide a summary of relevant drugs targeting IL-17A and their clinical trials. Here, we highlight the interactions between Th17 cells and neutrophils in diverse pathophysiological situations.

Neutrophil membrane-based nanotherapeutics: Propitious paradigm shift in the management of cancer

Cancer is the leading cause of death across the globe, with 19.3 million new cancer cases and 10 million deaths in the year 2020. Conventional treatment modalities have numerous pitfalls, such as off-site cytotoxicity and poor bioavailability. Nanocarriers (NCs) have been explored to deliver various therapeutic moieties such as chemotherapeutic agents and photothermal agents, etc. However, several limitations, such as rapid clearance by the reticuloendothelial system, poor extravasation into the tumor microenvironment, and low systemic half-life are roadblocks to successful clinical translation. To circumvent the pitfalls of currently available treatment modalities, neutrophil membrane (NM)-based nanotherapeutics have emerged as a promising platform for cancer management. Their versatile features such as natural tumor tropism, tumor-specific accumulation, and prevention from rapid clearance owing to their autologous nature make them an effective anticancer NCs. In this manuscript, we have discussed various methods for isolation, coating and characterization of NM. We have discussed the role of NM-coated nanotherapeutics as neoadjuvant and adjuvant in different treatment modalities, such as chemotherapy, photothermal and photodynamic therapies with rationales behind their inclusion. Clinical hurdles faced during the bench-to-bedside translation with possible solutions have been discussed. We believe that in the upcoming years, NM-coated nanotherapeutics will open a new horizon in cancer management.

The roles of immune cells in Behçet's disease

Behçet's disease (BD) is a systemic vasculitis that can affect multiple systems, including the skin, mucous membranes, joints, eyes, gastrointestinal and nervous. However, the pathogenesis of BD remains unclear, and it is believed that immune-inflammatory reactions play a crucial role in its development. Immune cells are a critical component of this process and contribute to the onset and progression of BD. By regulating the function of these immune cells, effective control over the occurrence and development of BD can be achieved, particularly with regards to monocyte activation and aggregation, macrophage differentiation and polarization, as well as T cell subset differentiation. This review provides a brief overview of immune cells and their role in regulating BD progression, which may serve as a theoretical foundation for preventing and treating this disease.

The role of neutrophil percentage to albumin ratio in predicting 1-year mortality in elderly patients with hip fracture and external validation

Objectives

This study aimed to investigate the association between the neutrophil percentage to albumin ratio (NPAR) on the day of admission and mortality 1 year after surgery in elderly patients with hip fractures.

Methods

Clinical characteristics and blood markers of inflammation were retrospectively collected from October 2016 to January 2022 in elderly patients with hip fractures at two different regional tertiary medical centers. It is divided into a training set and an external validation set. Multivariate Nomogram models such as NPAR were constructed using the least absolute shrinkage and selection operator (LASSO) regression results and multi-factor logistic regression analysis. In addition, multivariate Cox regression analysis and Kaplan-Meier survival curves were used to explore the relationship between NPAR values and mortality within 1 year in elderly patients with hip fractures. The predictive performance of the Nomogram was evaluated using the concordance index (C Index) and receiver operating characteristic curve (ROC) and validated by Bootstrap, Hosmer-Lemesow goodness of fit test, calibration curve, decision curve, and clinical impact curve analysis.

Results

The study included data from 1179 (mean age, 80.34 ± 8.06 years; 61.4[52.1%] male) patients from the Guangzhou Red Cross Hospital affiliated with Jinan University and 476 (mean age, 81.18 ± 8.33 years; 233 [48.9%] male) patients from the Xiaogan Central Hospital affiliated with Wuhan University of Science and Technology. The results showed that NPAR has good sensitivity and specificity in assessing patients' prognosis 1 year after surgery. Multivariate logistic regression models based on influencing factors such as NPAR have good discrimination and calibration ability (AUC=0.942, 95% CI:0.927-0.955; Hosmer-Lemeshow test: P >0.05). Kaplan-Meier survival curves for the training and validation sets showed that patients in the high NPAR group had a higher mortality rate at 1 year compared to the low NPAR group (P< 0.001). Multivariate Cox regression showed that high NPAR values were an independent risk factor for death within 1 year in elderly hip fracture patients (P< 0.001, HR =2.38,95%CI:1.84-3.08).

Conclusion

Our study showed that NPAR levels were significantly higher in patients who died within 1 year after surgery in both the training and validation sets. NPAR has good clinical value in assessing 1-year postoperative prognosis in elderly patients with hip fractures.

Diabetes-associated neutrophil NETosis: pathogenesis and interventional target of diabetic complications

Neutrophil extracellular traps (NETs) are known as extracellular fibers networks consisting of antimicrobial proteins and decondensated chromatin DNA released by activated neutrophils. NETosis is a NETs-induced neutrophilic cell death which is unique from necrosis or apoptosis. Besides its neutralizing pathogen, NETosis plays a crucial role in diabetes and diabetes-related complications. In patients with diabetes, NETs-releasing products are significantly elevated in blood, and these findings confirm the association of NETosis and diabetic complications, including diabetic wound healing, diabetic retinopathy, and atherosclerosis. This article briefly summarizes the mechanisms of NETosis and discusses its contribution to the pathogenesis of diabetes-related complications and suggests new therapeutic targets by some small molecule compounds.

Human blood neutrophils generate ROS through FcγR-signaling to mediate protection against febrile P. falciparum malaria

Blood phagocytes, such as neutrophils and monocytes, generate reactive oxygen species (ROS) as a part of host defense response against infections. We investigated the mechanism of Fcγ-Receptor (FcγR) mediated ROS production in these cells to understand how they contribute to anti-malarial immunity. Plasmodium falciparum merozoites opsonized with naturally occurring IgG triggered both intracellular and extracellular ROS generation in blood phagocytes, with neutrophils being the main contributors. Using specific inhibitors, we show that both FcγRIIIB and FcγRIIA acted synergistically to induce ROS production in neutrophils, and that NADPH oxidase 2 and the PI3K intracellular signal transduction pathway were involved in this process. High levels of neutrophil ROS were also associated with protection against febrile malaria in two geographically diverse malaria endemic regions from Ghana and India, stressing the importance of the cooperation between anti-malarial IgG and neutrophils in triggering ROS-mediated parasite killing as a mechanism for naturally acquired immunity against malaria.

Crosstalk between Thyroid Carcinoma and Tumor-Correlated Immune Cells in the Tumor Microenvironment

Thyroid cancer (TC) is the most common malignancy in the endocrine system. Although most TC can achieve a desirable prognosis, some refractory thyroid carcinomas, including radioiodine-refractory differentiated thyroid cancer, as well as anaplastic thyroid carcinoma, face a myriad of difficulties in clinical treatment. These types of tumors contribute to the majority of TC deaths due to limited initial therapy, recurrence, and metastasis of the tumor and tumor resistance to current clinically targeted drugs, which ultimately lead to treatment failure. At present, a growing number of studies have demonstrated crosstalk between TC and tumor-associated immune cells, which affects tumor deterioration and metastasis through distinct signal transduction or receptor activation. Current immunotherapy focuses primarily on cutting off the interaction between tumor cells and immune cells. Since the advent of immunotherapy, scholars have discovered targets for TC immunotherapy, which also provides new strategies for TC treatment. This review methodically and intensively summarizes the current understanding and mechanism of the crosstalk between distinct types of TC and immune cells, as well as potential immunotherapy strategies and clinical research results in the area of the tumor immune microenvironment. We aim to explore the current research advances to formulate better individualized treatment strategies for TC patients and to provide clues and references for the study of potential immune checkpoints and the development of immunotherapy technologies.

The Involvement of Neutrophil in the Immune Dysfunction Associated with BVDV Infection

Bovine viral diarrhea virus (BVDV) induces immune dysfunction that often results in a secondary bacterial infection in the infected animals. The underlying mechanism of BVDV-induced immune dysfunction is not well understood. The role of BVDV-infected macrophage-secreted factors was investigated. BVDV-infected monocyte-derived macrophage (MDM) supernatants down-regulated the expression of neutrophil L-selectin and CD18. Regardless of the biotype, phagocytic activity and oxidative burst were downregulated by BVDV-infected MDM supernatants. However, only supernatants from cytopathic (cp) BVDV down-regulated nitric oxide production and neutrophil extracellular traps (NET) induction. Our data suggested that BVDV-induced macrophage-secreted factors caused immune dysfunction in neutrophils. Unlike lymphocyte depletion, the negative impact on neutrophils seems to be specific to cp BVDV biotype. Interestingly the majority of modified live BVDV vaccines are based on cp strain of BVDV.

Neutrophil diversity in inflammation and cancer

Neutrophils are the most abundant circulating leukocytes in humans and the first immune cells recruited at the site of inflammation. Classically perceived as short-lived effector cells with limited plasticity and diversity, neutrophils are now recognized as highly heterogenous immune cells, which can adapt to various environmental cues. In addition to playing a central role in the host defence, neutrophils are involved in pathological contexts such as inflammatory diseases and cancer. The prevalence of neutrophils in these conditions is usually associated with detrimental inflammatory responses and poor clinical outcomes. However, a beneficial role for neutrophils is emerging in several pathological contexts, including in cancer. Here we will review the current knowledge of neutrophil biology and heterogeneity in steady state and during inflammation, with a focus on the opposing roles of neutrophils in different pathological contexts.

ETV4 Mediated Tumor-Associated Neutrophil Infiltration Facilitates Lymphangiogenesis and Lymphatic Metastasis of Bladder Cancer

As a key step of tumor lymphatic metastasis, lymphangiogenesis is regulated by VEGFC-VEGFR3 signaling pathway mediated by immune cells, mainly macrophages, in the tumor microenvironment. However, little is known whether tumor associated neutrophils are involved in lymphangiogenesis. Here, it is found that TANs infiltration is increased in LN-metastatic BCa and is associated with poor prognosis. Neutrophil depletion results in significant reduction in popliteal LN metastasis and lymphangiogenesis. Mechanistically, transcription factor ETV4 enhances BCa cells-derived CXCL1/8 to recruit TANs, leading to the increase of VEGFA and MMP9 from TANs, and then facilitating lymphangiogenesis and LN metastasis of BCa. Moreover, phosphorylation of ETV4 at tyrosine 392 by tyrosine kinase PTK6 increases nuclear translocation of ETV4 and is essential for its function in BCa. Overall, the findings reveal a novel mechanism of how tumor cells regulate TANs-induced lymphangiogenesis and LN metastasis and identify ETV4 as a therapeutic target of LN metastasis in BCa.

Innate immune responses in pneumonia

The lungs are an immunologically unique environment; they are exposed to innumerable pathogens and particulate matter daily. Appropriate clearance of pathogens and response to pollutants is required to prevent overwhelming infection, while preventing tissue damage and maintaining efficient gas exchange. Broadly, the innate immune system is the collection of immediate, intrinsic immune responses to pathogen or tissue injury. In this review, we will examine the innate immune responses of the lung, with a particular focus on their role in pneumonia. We will discuss the anatomic barriers and antimicrobial proteins of the lung, pathogen and injury recognition, and the role of leukocytes (macrophages, neutrophils, and innate lymphocytes) and lung stromal cells in innate immunity. Throughout the review, we will focus on new findings in innate immunity as well as features that are unique to the lung.

The neutrophil-to-lymphocyte and monocyte-to-lymphocyte ratios are independently associated with clinical outcomes of viral encephalitis

Background

The neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR) are used as prognostic biomarkers for many diseases. In this study, we aimed to explore the possibility of using ratios of NLR and MLR to predict the prognosis of viral encephalitis (VE).

Methods

A total of 81 patients with an initial diagnosis of VE who were admitted to our hospital from January 2018 to January 2021 were retrospectively analyzed. A routine blood test within 24 h of admission was utilized to determine the ratios of NLR and MLR for each patient. The modified Rankin Scale (mRS) at 12 months after discharge was used to evaluate patients' clinical prognosis and the patients were divided into the group of good prognosis (mRS ≤ 1) and the group of poor prognosis (mRS ≥ 2) according to the mRS scores. Univariate and multivariable regression analyses were used to differentiate and assess independent prognostic factors for the prognosis of VE.

Results

Neutrophil-to-lymphocyte ratio and MLR of the poor prognosis group were significantly higher than that of the good prognosis group. Multivariate logistic regression analysis results showed that NLR [odds ratio (OR): 1.421, 95% confidence interval (CI): 1.105-1.827; P < 0.05] and MLR (OR: 50.423, 95% CI: 2.708-939.001; P < 0.05) were independent risk factors for the poor prognosis of VE. NLR > 4.32 and MLR > 0.44 were suggested as the cutoff threshold for the prediction of the poor prognosis of VE.

Conclusion

Neutrophil-to-lymphocyte ratio and MLR obtained from blood tests done at hospital admission have the potential to predict poor prognosis in patients with VE.

Dental Pulp Inflammation Initiates the Occurrence of Mast Cells Expressing the α1 and β1 Subunits of Soluble Guanylyl Cyclase

The binding of nitric oxide (NO) to heme in the β₁ subunit of soluble guanylyl cyclase (sGC) activates both the heterodimeric α₁β₁ and α₂β₁ isoforms of the enzyme, leading to the increased production of cGMP from GTP. In cultured human mast cells, exogenous NO is able to inhibit mast cell degranulation via NO-cGMP signaling. However, under inflammatory oxidative or nitrosative stress, sGC becomes insensitive to NO. The occurrence of mast cells in healthy and inflamed human tissues and the in vivo expression of the α₁ and β₁ subunits of sGC in human mast cells during inflammation remain largely unresolved and were investigated here. Using peroxidase and double immunohistochemical incubations, no mast cells were found in healthy dental pulp, whereas the inflammation of dental pulp initiated the occurrence of several mast cells expressing the α₁ and β₁ subunits of sGC. Since inflammation-induced oxidative and nitrosative stress oxidizes Fe²⁺ to Fe³⁺ in the β₁ subunit of sGC, leading to the desensitization of sGC to NO, we hypothesize that the NO- and heme-independent pharmacological activation of sGC in mast cells may be considered as a regulatory strategy for mast cell functions in inflamed human dental pulp.

Trained immunity can improve the disease resistance of red swamp crayfish (Procambarus clarkii)

Trained immunity has been widely observed in mammals. Its identification in red swamp crayfish (Procambarus clarkii) is important for disease resistance in the crayfish farming industry. In this study, the mortality, expression of immune genes, production of reactive oxygen species (ROS), and phagocytosis ability of haemocytes in crayfish infected by pathogens (Vibrio parahaemolyticus or white spot syndrome virus) and crayfish trained with β-glucan or PBS (the control) were assessed when they were re-challenged by the pathogens. The results showed that the mortality of the trained and re-challenged crayfish were significantly lower than those of the untrained and challenged crayfish. Furthermore, the expression of immune genes, including Resistance (R), ALF, crustin2, and proPO, ROS levels, and phagocytosis ability of haemocytes, was significantly improved in the trained crayfish compared to that in the untrained crayfish. Interestingly, we found that the immune memory of trained crayfish lasted for at least 18 days. Together, these results indicate that crayfish develops trained immunity that can play an important role in the disease resistance. This suggests that trained immunity may be applied to improve disease resistance and crayfish production.

The Relationship Between the Neutrophil Percentage-to-Albumin Ratio and Rates of 28-Day Mortality in Atrial Fibrillation Patients 80 Years of Age or Older

Backgrounds and Aims

Atrial fibrillation (AF) is the most common cardiac arrhythmia among the older patients (≥ 80 years) in clinical practice. The index of neutrophil percentage-to-albumin ratio (NPAR) is a reliable predictor of adverse outcomes in cardiovascular diseases. There is scarce evidence regarding the association between NPAR and mortality among the older patients with AF.

Methods

The research was conducted among 1141 patients with AF between January 2015 and June 2020, hospitalized at Huadong Hospital affiliated with Fudan University. The primary outcome were 28-day all-cause and cardiovascular mortality. Cox regression analysis and Kaplan-Meier survival curves were used to explore the correlation between NPAR and 28-day all-cause or cardiovascular mortality. Receiver operating characteristic (ROC) curve and the area under the curve (AUC) were performed for the predictive values of NPAR on prognosis.

Results

The 28-day death rate from cardiovascular disease and all-causes were 3.3% and 8.7%, respectively. Continuous NPAR levels were positively associated with all-cause (HR 1.13, 95% CI 1.09, 1.16) and cardiovascular (HR 1.16, 95% CI 1.10, 1.23) mortality after adjustment for confounding variables. Relative to patients in the T1 group, those in higher NPAR tertiles also exhibit elevated risks of all-cause (P < 0.001) and cardiovascular mortality (P < 0.001). Furthermore, both all-cause and cardiovascular mortality rates rose with increasing NPAR in all analyzed subgroups.

Conclusion

NPAR values are consistently positively related to 28-day all-cause and cardiovascular mortality rates in patients ≥80 years of age with AF.

Benzyl isothiocyanate improves the prognosis of Aspergillus fumigatus keratitis by reducing fungal load and inhibiting Mincle signal pathway

Aspergillus fumigatus keratitis is a potential blinding disease associated with A. fumigatus invasion and excessive inflammatory response. Benzyl isothiocyanate (BITC) is a secondary metabolite with broad antibacterial and anti-inflammatory activity extracted from cruciferous species. However, the role of BITC in A. fumigatus keratitis has not been discovered yet. This study aims to explore the antifungal and anti-inflammatory effects and mechanisms of BITC in A. fumigatus keratitis. Our results provided evidences that BITC exerted antifungal effects against A. fumigatus by damaging cell membranes, mitochondria, adhesion, and biofilms in a concentration-dependent manner. In vivo, fungal load and inflammatory response including inflammatory cell infiltration and pro-inflammatory cytokine expression were reduced in BITC-treated A. fumigatus keratitis. Additionally, BITC significantly decreased Mincle, IL-1β, TNF-α, and IL-6 expression in RAW264.7 cells that stimulated by A. fumigatus or Mincle ligand trehalose-6,6-dibehenate. In summary, BITC possessed fungicidal activities and could improve the prognosis of A. fumigatus keratitis by reducing fungal load and inhibiting the inflammatory response mediated by Mincle.

Elevated plasma D-dimer levels in patients with anti-N-methyl-D-aspartate receptor encephalitis

PURPOSE

We aimed to explore the difference in coagulation function between healthy individuals and patients with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis and its relationship with disease severity.

METHODS

We retrospectively compared coagulation function in 161 patients with first-attack anti-NMDAR encephalitis and 178 healthy individuals. The association between D-dimer levels and disease severity was analyzed using binary logistic regression. Receiver operating characteristic (ROC) curves were used to analyze the predictive value of D-dimer levels for the severity of anti-NMDAR encephalitis.

RESULTS

Compared to control individuals, patients with anti-NMDAR encephalitis had higher D-dimer levels (median 0.14 vs. 0.05 mg/L, p < 0.001), blood white blood cell (WBC) count (median 8.54 vs. 5.95 × 109/L, p < 0.001), and neutrophil count (median 6.14 vs. 3.1 × 109/L, p < 0.001). D-dimers (median 0.22 vs. 0.10 mg/L, p < 0.001), blood WBC count (median 9.70 vs. 7.70 × 109/L, p < 0.001), neutrophil count (median 7.50 vs. 4.80 × 109/L, p < 0.001), and C-reactive protein (median 2.61 vs. 1.50 mg/l, p = 0.017) were higher; however, eosinophils (median 0.02 vs. 0.06 × 109/L, p < 0.001), and blood calcium (median 2.26 vs. 2.31 mmol/L, p = 0.003) were lower in patients with severe forms of anti-NMDAR encephalitis than in those with mild to moderate forms, and were associated with initial modified Rankin Scale scores. Multivariate analysis showed that D-dimer levels were significantly associated with severity [odds ratio =2.631, 95% confidence interval (CI) = 1.018-6.802, p = 0.046]. The ROC curve was used to analyze the predictive value of D-dimer levels for disease severity. The area under the curve was 0.716 (95% CI = 0.64-0.80, p < 0.001), and the best cut-off value was D-dimer = 0.147 mg/L (sensitivity 0.651; specificity, 0.705).

CONCLUSION

Serum D-dimer and neutrophil levels were independent predictors of disease severity in patients with first-attack anti-NMDAR encephalitis.

Leukocyte metabolism in obese type 2 diabetic individuals associated with COVID-19 severity

Recent studies show that the metabolic characteristics of different leukocytes, such as, lymphocytes, neutrophils, and macrophages, undergo changes both in the face of infection with SARS-CoV-2 and in obesity and type 2 diabetes mellitus (DM2) condition. Thus, the objective of this review is to establish a correlation between the metabolic changes caused in leukocytes in DM2 and obesity that may favor a worse prognosis during SARS-Cov-2 infection. Chronic inflammation and hyperglycemia, specific and usual characteristics of obesity and DM2, contributes for the SARS-CoV-2 replication and metabolic disturbances in different leukocytes, favoring the proinflammatory response of these cells. Thus, obesity and DM2 are important risk factors for pro-inflammatory response and metabolic dysregulation that can favor the occurrence of the cytokine storm, implicated in the severity and high mortality risk of the COVID-19 in these patients.

Moderate exercise relieves fluoride-induced liver and kidney inflammatory responses through the IKKβ/NFκB pathway

With the intensification of environmental pollution, the content of fluoride is increasing in human and animal living environments. Long-term fluoride exposure can cause damage to the liver and kidney, which are the main sites for fluoride metabolism, storage and removal. Moreover, exercise often accompanies the entire process of fluoride exposure in humans and animals. However, the mechanism of exercise on fluoride-induced liver and kidney injury remains unclear. Hence, we established a fluoride exposure and/or exercise mouse model to explore the influence of exercise on fluoride-induced liver and kidney inflammation and the potential mechanism. The results showed that fluoride caused obvious structural and functional damage and the notable recruitment of immunocytes in the liver and kidney. In addition, fluoride increased the levels of IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, IL-21, TNF-α, and TGF-β but decreased the ratio of IFN-γ/IL-4 and IL-2/IL-10, which indicated that fluoride disturbed the inflammatory balance and caused hepatonephritis. In addition, the expression levels of IKKβ and NFκB were increased, and the expression of IκBα was decreased after fluoride exposure, indicating that fluoride activated the IKKβ/NFκB pathway. In summary, long-term moderate treadmill exercise relieved fluoride-induced liver and kidney inflammatory responses through the IKKβ/NFκB pathway, and exercise can be used to prevent fluoride-induced liver and kidney damage.

Role of lymphocyte-related immune-inflammatory biomarkers in detecting early progression of Guillain-Barré syndrome

OBJECTIVES

This study aimed to investigate the role of peripheral neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), and platelet to lymphocyte ratio (PLR) in the progression and severity of the Guillain-Barré syndrome (GBS).

METHODS

47 GBS patients and 50 age and sex-matched healthy controls (HC) were retrospectively included. Demographic and clinical assessment data were reviewed and abstracted. NLR, MLR, and PLR were calculated based on the peripheral blood tests by reviewing clinical data. The relationship between the Hughes' score and NLR, MLR, PLR levels was investigated.

RESULTS

The GBS patients had higher NLR levels (P < 0.001), MLR levels (P = 0.001) and PLR levels (P < 0.001) than those in HC. And patients with severe disability score (Hughes' score ≥ 3) had significantly higher NLR (P = 0.007), MLR (P = 0.04), PLR (P = 0.013). Spearman correlation analysis indicated that NLR was positively associated with the Hughes' score (r = 0.331, P = 0.023). In the patients with acute inflammatory demyelinating polyneuropathy (AIDP), Spearman correlation analysis indicated that NLR, MLR and PLR were positively associated to the Hughes' score (r = 0.825, P = 0.001 for NLR, r = 0.727, P = 0.005 for MLR, and r = 0.723, P = 0.005 for PLR).

CONCLUSIONS

NLR, MLR, and PLR may be indicators of disease activity in patients with GBS or AIDP. These parameters may benefit the active treatment of GBS patients with a high degree of disability.

The Immune Landscape of Papillary Thyroid Cancer in the Context of Autoimmune Thyroiditis

Simple Summary

The association between papillary thyroid cancer and Hashimoto’s thyroiditis went through a long-standing human debate recently elucidated by the establishment of a novel mouse model. Papillary thyroid carcinoma is an excellent model for studying the tumor immune microenvironment because it is naturally accompanied by immune cells, making it a good candidate for the treatment with immune checkpoint inhibitors.

Abstract

Papillary thyroid cancer (PTC) often co-occurs with Hashimoto’s thyroiditis, an association that has long been reported in clinical studies, remaining controversial. Experimental evidence has recently shown that pre-existing thyroiditis has a beneficial effect on PTC growth and progression by a distinctive expansion of effector memory CD8 T cells. Although the link between inflammation and PTC might involve different components of the immune system, a deep characterization of them which includes T cells, B cells and tertiary lymphoid structures, Mye-loid cells, Neutrophils, NK cells and dendritic cells will be desirable. The present review article considers the role of the adaptive and innate immune response surrounding PTC in the context of Hashimoto’s thyroiditis. This review will focus on the current knowledge by in vivo and in vitro studies specifically performed on animals’ models; thyroid cancer cells and human samples including (i) the dual role of tumor-infiltrating lymphocytes; (ii) the emerging role of B cells and tertiary lymphoid structures; (iii) the role of myeloid cells, dendritic cells, and natural killer cells; (iv) the current knowledge of the molecular biomarkers implicated in the complex link between thyroiditis and PTC and the potential implication of cancer immunotherapy in PTC patients in the context of thyroiditis.

Altered sialidase expression in human myeloid cells undergoing apoptosis and differentiation

To gain insight into sialic acid biology and sialidase/neuraminidase (NEU) expression in mature human neutrophil (PMN)s, we studied NEU activity and expression in PMNs and the HL60 promyelocytic leukemic cell line, and changes that might occur in PMNs undergoing apoptosis and HL60 cells during their differentiation into PMN-like cells. Mature human PMNs contained NEU activity and expressed NEU2, but not NEU1, the NEU1 chaperone, protective protein/cathepsin A(PPCA), NEU3, and NEU4 proteins. In proapoptotic PMNs, NEU2 protein expression increased > 30.0-fold. Granulocyte colony-stimulating factor protected against NEU2 protein upregulation, PMN surface desialylation and apoptosis. In response to 3 distinct differentiating agents, dimethylformamide, dimethylsulfoxide, and retinoic acid, total NEU activity in differentiated HL60 (dHL60) cells was dramatically reduced compared to that of nondifferentiated cells. With differentiation, NEU1 protein levels decreased > 85%, PPCA and NEU2 proteins increased > 12.0-fold, and 3.0-fold, respectively, NEU3 remained unchanged, and NEU4 increased 1.7-fold by day 3, and then returned to baseline. In dHL60 cells, lectin blotting revealed decreased α2,3-linked and increased α2,6-linked sialylation. dHL60 cells displayed increased adhesion to and migration across human bone marrow-derived endothelium and increased bacterial phagocytosis. Therefore, myeloid apoptosis and differentiation provoke changes in NEU catalytic activity and protein expression, surface sialylation, and functional responsiveness.

Following successful anti-leishmanial treatment, neutrophil counts, CD10 expression and phagocytic capacity remain reduced in visceral leishmaniasis patients co-infected with HIV

Visceral leishmaniasis (VL) patients co-infected with HIV (VL/HIV patients) experience frequent treatment failures, VL relapses, opportunistic infections, and higher mortality. Their immune system remains profoundly suppressed after clinical cure and they maintain higher parasite load. This is in contrast with patients with VL alone (VL patients). Since neutrophils play a critical role in the control of Leishmania replication and the regulation of immune responses, we tested the hypothesis that neutrophil activation status and effector functions are fully restored in VL, but not in VL/HIV patients. Our results show the neutrophil counts and all activation markers and effector functions tested in our study were reduced at the time of diagnosis in VL and VL/HIV patients as compared to controls. CD62L, CD63, arginase 1 expression levels and reactive oxygen species production were restored at the end of treatment in both groups. However, neutrophil counts, CD10 expression and phagocytosis remained significantly lower throughout follow-up in VL/HIV patients; suggesting that dysregulated neutrophils contribute to the impaired host defence against pathogens in VL/HIV patients.

Clinical Characteristics and Prognosis of Antibody-Negative Autoimmune Encephalitis in Children: A Single-Center Retrospective Study

BACKGROUND

Autoimmune encephalitis (AE) is a group of immune-mediated brain diseases. However, new diagnostic criteria for AE in children indicate that partial pediatric patients with AE may be diagnosed without evidence of positive autoantibodies. Therefore, the clinical characteristics and prognosis of children with antibody-negative but probable AE require further investigation.

METHODS

Forty-one children with AE admitted to our hospital from April 2014 to January 2021 were retrospectively enrolled in this study. Children were divided into two groups according to positive or negative antibody tests. Clinical characteristics, cerebrospinal fluid, video electroencephalography, brain magnetic resonance imaging, and prognosis were analyzed, and the correlation between modified Rankin scale (mRS) and neutrophil-to-lymphocyte ratio (NLR) was examined.

RESULTS

Of 41 children, 16 cases tested positive for autoantibodies. The main features were psychiatric symptoms, cognitive disturbances, speech disturbances, movement disorders, and seizures. All the children were given a combination of intravenous methylprednisolone pulses with intravenous immunoglobulin therapy; 26 cases (63%) had a good outcome, and 15 cases (37%) had a poor outcome. Antibody-positive and antibody-negative but probable AE were analyzed by univariate analysis and showed lower lymphocyte counts and higher NLR and mRS scores in the antibody-negative group (P < 0.05). The Spearman rank correlation analysis showed a positive correlation between NLR level and mRS scores (P < 0.05).

CONCLUSIONS

Antibody-negative but possible AE is frequent in children who may have a more severe neurological impairment and higher NLR than antibody-positive AE. Aggressive immunotherapy in antibody-negative AE is essential to achieve a good prognosis.

The Dual Role of Innate Immune Response in Acetaminophen-Induced Liver Injury

Acetyl-para-aminophenol (APAP), a commonly used antipyretic analgesic, is becoming increasingly toxic to the liver, resulting in a high rate of acute hepatic failure in Europe and the United States. Excessive APAP metabolism in the liver develops an APAP-protein adduct, which causes oxidative stress, MPTP opening, and hepatic necrosis. HMGB-1, HSP, nDNA, mtDNA, uric acid, and ATP are DMAPs released during hepatic necrosis. DMAPs attach to TLR4-expressing immune cells such KCs, macrophages, and NK cells, activating them and causing them to secrete cytokines. Immune cells and their secreted cytokines have been demonstrated to have a dual function in acetaminophen-induced liver injury (AILI), with a role in either proinflammation or pro-regeneration, resulting in contradicting findings and some research confusion. Neutrophils, KCs, MoMFs, NK/NKT cells, γδT cells, DCs, and inflammasomes have pivotal roles in AILI. In this review, we summarize the dual role of innate immune cells involved in AILI and illustrate how these cells initiate innate immune responses that lead to persistent inflammation and liver damage. We also discuss the contradictory findings in the literature and possible protocols for better understanding the molecular regulatory mechanisms of AILI.

The Neutrophil-to-Lymphocyte and Monocyte-to-Lymphocyte Ratios Are Independently Associated With the Severity of Autoimmune Encephalitis

Background

The neutrophil-to-lymphocyte ratio (NLR) and monocyte-to-lymphocyte ratio (MLR) are biomarkers that may reflect inflammatory status in some immune-related diseases. This study aims to investigate the association of NLR and MLR with the severity and prognosis of autoimmune encephalitis (AE).

Methods

A total of 199 patients diagnosed with AE in the First Affiliated Hospital of Zhengzhou University from October 2015 to October 2021 were retrospectively analyzed. The Clinical Assessment Scale for Autoimmune Encephalitis (CASE) and the modified Rankin Scale (mRS) were used to evaluate the severity of the patients at admission, and the patients were divided into mild group (CASE ≤ 4) and severe group (CASE ≥ 5) according to the CASE score. Poor prognosis was described as an mRS of 3 or more at 12 months. Binary logistic regression analysis was performed to assess risk factors for the severity and prognosis of AE.

Results

NLR and MLR of severe group were significantly higher than that of mild group. NLR and MLR were positively correlated with the CASE score (r = 0.659, P < 0.001; r = 0.533, P < 0.001) and the mRS score (r = 0.609, P < 0.001;r = 0.478, P < 0.001) in AE patients. Multivariate logistic analysis showed that NLR (OR = 1.475, 95%CI: 1.211-1.796, P < 0.001) and MLR (OR = 15.228, 95%CI: 1.654-140.232, P = 0.016) were independent risk factors for the severity of AE. In addition, the CASE score and the mRS score were positively correlated (r = 0.849, P < 0.001). Multivariate logistic analysis showed that the CASE at admission (OR = 1.133, 95%CI: 1.043-1.229, P = 0.003) and age (OR = 1.105, 95%CI: 1.062-1.150, P < 0.001) were independent risk factors for the poor prognosis of AE patients. The NLR and MLR at admission and whether they decreased after immunotherapy were not associated with the prognosis of AE patients (P > 0.05).

Conclusions

NLR and MLR, readily available and widespread inflammatory markers, were helpful for clinicians to monitor disease progression and identify potentially severe patients of AE early to optimize clinical treatment decisions.

Elevated plasma level of the glycolysis byproduct methylglyoxal on admission is an independent biomarker of mortality in ICU COVID-19 patients

Biomarkers to identify ICU COVID-19 patients at high risk for mortality are urgently needed for therapeutic care and management. Here we found plasma levels of the glycolysis byproduct methylglyoxal (MG) were 4.4-fold higher in ICU patients upon admission that later died (n = 33), and 1.7-fold higher in ICU patients that survived (n = 32),compared to uninfected controls (n = 30). The increased MG in patients that died correlated inversely with the levels of the MG-degrading enzyme glyoxalase-1 (r² = - 0.50), and its co-factor glutathione (r² = - 0.63), and positively with monocytes (r² = 0.29). The inflammation markers, SSAO (r² = 0.52), TNF-α (r² = 0.41), IL-1β (r² = 0.25), CRP (r² = 0.26) also correlated positively with MG. Logistic regression analysis provides evidence of a significant relationship between the elevated MG upon admission into ICU and death (P < 0.0001), with 42% of the death variability explained. From these data we conclude that elevated plasma MG on admission is a novel independent biomarker that predicts mortality in ICU COVID-19 patients.

Pretreatment Systemic Immune-Inflammation Index Can Predict Response to Neoadjuvant Chemotherapy in Cervical Cancer at Stages IB2-IIB

Background: The systemic immune-inflammation index (SII) has been identified as a predictor of chemotherapy efficacy for a variety of cancers, and we aimed to determine its ability to predict the response to chemotherapy and its long-term prognosis for patients with cervical squamous cell carcinoma (CSCC) who have underwent platinum-based neoadjuvant chemotherapy (NACT).

Methods: The date from 210 patients (133 in the training cohort and 77 in the validation cohort) with CSCC who received NACT were analyzed retrospectively. The association between SII and the pathological complete response (pCR) was determined using Pearson’s chi-square test, receiver operating characteristic (ROC) curve, and Logistic regression analysis. The Kaplan-Meier method and Cox proportional regression model were used to assess the relationship between SII and progression-free survival (PFS) or overall survival (OS).

Results: The calculated optimal SII cutoff values for pCR and survival were 568.7051 and 600.5683, respectively, and patients were divided into two groups: a low SII group (≤568.7051 or ≤600.5683) and a high SII group (>568.7051 or >600.5683). A high SII was associated significantly with a lower pCR. Further analysis determined that SII was a more efficient predictor of pCR than the prognostic nutritional index, platelet-to-lymphocyte ratio, and lymphocyte-to-monocyte ratio. Upon multivariate logistic analysis, SII proved to be an independent risk factor to predict the pCR of patients with CSCC. Kaplan-Meier analysis demonstrated that PFS and OS rates were significantly higher in the low-SII group compared with those in the high-SII group. Additional multivariate analysis indicated that the SII is an independent prognostic factor for patients with CSCC treated with NACT.

Conclusion: The results confirmed that the pre-treatment SII is not only an independent predictor of pCR but also an independent prognostic factor of CSCC patients treated with platinum based NACT.

Lung Hyaluronasome: Involvement of Low Molecular Weight Ha (Lmw-Ha) in Innate Immunity

Hyaluronic acid (HA) is a major component of the extracellular matrix. It is synthesized by hyaluronan synthases (HAS) into high-molecular-weight chains (HMW-HA) that exhibit anti-inflammatory and immunomodulatory functions. In damaged, infected, and/or inflamed tissues, HMW-HA are degraded by hyaluronidases (HYAL) or reactive oxygen species (ROS) to give rise to low-molecular-weight HAs (LMW-HAs) that are potent pro-inflammatory molecules. Therefore, the size of HA regulates the balance of anti- or pro-inflammatory functions. The activities of HA depend also on its interactions with hyaladherins. HA synthesis, degradation, and activities through HA/receptors interactions define the hyaluronasome. In this review, a short overview of the role of high and low-molecular-weight HA polymers in the lungs is provided. The involvement of LMW-HA in pulmonary innate immunity via the activation of neutrophils, macrophages, dendritic cells, and epithelial cells is described to highlight LMW-HA as a therapeutic target in inflammatory respiratory diseases. Finally, the possibilities to counter LMW-HA’s deleterious effects in the lungs are discussed.

Neutrophil Percentage-to-Albumin Ratio: A Good Parameter for the Evaluation of the Severity of Anti-NMDAR Encephalitis at Admission and Prediction of Short-Term Prognosis

Objectives

The purpose of this study was to investigate the association of neutrophil percentage-to-albumin ratio (NPAR) with the severity at admission and discharge (short-term prognosis) in patients with anti-N-methyl-D-aspartic acid receptor (NMDAR) encephalitis.

Methods

Multivariable logistic regression models such as NPAR were constructed based on univariable regression results. Receiver operating characteristic (ROC) curves, nomograms, and concordance index (c-index) were used to evaluate the efficacy of the models in assessing disease severity at admission and predicting short-term prognosis, validated by bootstrap, Hosmer–Lemeshow goodness-of-fit test, calibration curves, and decision curve analysis.

Results

A total of 181 patients with anti-NMDAR encephalitis diagnosed at the First Affiliated Hospital of Zhengzhou University were included. The results showed that NPAR had good sensitivity and specificity in assessing disease severity at admission and predicting short-term prognosis. The multivariable logistic regression models based on NPAR and other influencing factors had good discrimination, consistency, accuracy, calibration ability, applicability, and validity in assessing the severity at admission and predicting short-term prognosis.

Conclusion

NPAR has good clinical value in assessing disease severity at admission and predicting short-term prognosis of patients with anti-NMDAR encephalitis.

Association between Neutrophil Levels on Admission and All-Cause Mortality in Geriatric Patients with Hip Fractures: A Prospective Cohort Study of 2,589 Patients

OBJECTIVE

To evaluate the association between neutrophil levels and all-cause mortality in geriatric hip fractures.

METHODS

Elderly patients with hip fractures were screened between January 2015 and September 2019. Demographic and clinical characteristics of the patients were collected. Linear and nonlinear multivariate Cox regression models were used to identify the association between neutrophil levels and mortality. Analyses were performed using Empower Stats and R software.

RESULTS

A total of 2,589 patients were included in this study. The mean follow-up period was 38.95 months. During the study period, 875 (33.80%) patients died due to various causes. Linear multivariate Cox regression models showed that neutrophil levels were associated with mortality after adjusting for confounding factors, when neutrophil concentration increased by 1∗10⁹/L, the mortality risk increased by 3% (HR = 1.03, 95% CI: 1.00-1.06, and P=0210). Neutrophil concentration was used as a categorical variable; we only found statistically significant differences when neutrophil levels were high (HR = 1.27, 95% CI:1.05-1.52, and P=0.0122). In addition, the results are stable in P for trend and propensity score matching sensitivity analysis.

CONCLUSIONS

Neutrophil levels are associated with mortality in geriatric hip fractures and could be considered a predictor of death risk in the long-term. This study is registered with the Chinese Clinical Trial Registry (ChiCTR) as number ChiCTR2200057323.

Therapeutic exploitation of neutrophils to fight cancer

Antibody-based immunotherapy is a promising strategy in cancer treatment. Antibodies can directly inhibit tumor growth, induce complement-dependent cytotoxicity and induce Fc receptor-mediated elimination of tumor cells by macrophages and natural killer cells. Until now, however, neutrophils have been largely overlooked as potential effector cells, even though they are the most abundant type of immune cells in the circulation. Neutrophils display heterogeneity, especially in the context of cancer. Therefore, their role in cancer is debated. Nevertheless, neutrophils possess natural anti-tumor properties and appropriate stimulation, i.e. specific targeting via antibody therapy, induces potent tumor cell killing, especially via targeting of the immunoglobulin A Fc receptor (FcαRI, CD89). In this review we address the mechanisms of tumor cell killing by neutrophils and the role of neutrophils in induction of anti-tumor immunity. Moreover, possibilities for therapeutic targeting are discussed.

Zinc-dependent histone deacetylases drive neutrophil extracellular trap formation and potentiate local and systemic inflammation

Neutrophil extracellular traps (NETs) have been implicated in the pathogenesis of acute respiratory distress syndrome (ARDS) driven by viruses or bacteria, as well as in numerous immune-mediated disorders. Histone citrullination by the enzyme peptidylarginine deiminase 4 (PAD4) and the consequent decondensation of chromatin are hallmarks in the induction of NETs. Nevertheless, additional histone modifications that may govern NETosis are largely overlooked. Herein, we show that histone deacetylases (HDACs) play critical roles in driving NET formation in human and mouse neutrophils. HDACs belonging to the zinc-dependent lysine deacetylases family are necessary to deacetylate histone H3, thus allowing the activity of PAD4 and NETosis. Of note, HDAC inhibition in mice protects against microbial-induced pneumonia and septic shock, decreasing NETosis and inflammation. Collectively, our findings illustrate a new fundamental step that governs the release of NETs and points to HDAC inhibitors as therapeutic agents that may be used to protect against ARDS and sepsis.